Airflow control in heating and air-conditioning units

ABSTRACT

The present invention relates to the field of directing ventilating air and airflow control in a ventilating, heating or air conditioning system. More specifically, the present invention relates to a structure and method to provide air flow mixture via an air mixer structure or ‘baffle’ located within a blend door. The simplified HVAC unit provides a baffle/blend door assembly comprising an air mixer structure wherein the attachment means of baffle and barrel door is such that it provides for ease of assembly. The baffle/barrel door assembly provides for smaller packaging volume with the same functionality as larger HVAC units.

This application is a continuation in part of Ser. No. 10/729,456 filedDec. 5, 2003

FIELD OF THE INVENTION

The present invention relates generally to airflow control in heatingand air conditioning units, particularly for automotive purposes.

BACKGROUND OF THE INVENTION

The present invention relates to the field of directing ventilating airand airflow control in a ventilating, heating or air conditioningsystem. More specifically, the present invention relates to a structureand method to provide air flow mixture via an air mixer structurelocated within a blend door.

DESCRIPTION OF THE PRIOR ART

In automotive ventilating systems and in ventilating systems in general,air needs to be directed to desired areas through respective airpassageways. The air can be directed via outlet means such as dampers,doors and various mechanisms so the area that the ventilating systemdesigner desires to have the air proceed to is achieved under anyselected design conditions. For example, a design may provide for heatedor cooled air to pass through an area or zone where it mixes to providea certain temperature of air based on the area in the passengercompartment of a vehicle to which the air will be finally directed. ManyHVAC architectures however, are flawed due to limitations in partsmanufacture, tooling and assembly of said parts.

Ventilating, heating and air conditioning systems in modern vehiclesstrive to provide a total interior climate control. Such systemsmaintain a desired temperature by delivering an appropriate mix ofambient, cooled and heated air to the vehicle interior. Such systemsconventionally include an air duct, which is selectively connected tothe external air or to the interior of the vehicle cabin, a fan forcausing the air to flow, and an evaporator unit within the duct forcooling the air. The cold air output from the evaporator unit may besupplied directly to various outlets within the vehicle cabin or some ofthe cold air may be passed through a heating heat exchanger whose heatedair output is mixed with the cold air to provide temperature control ofthe air output to the cabin. Diversion of the cold air through the heatexchanger in some prior art is controlled by a so-called “blend door”,which in one extreme position causes all of the cold air to flow throughthe heat exchanger and in the opposite extreme position causes none ofthe air to flow through the heat exchanger. In intermediate positions,different proportions of cold air and heated air can be provided. Blenddoors (those that send air to the distribution areas prior todistribution and mode doors that take this air and direct it into theducts for final distribution in automotive vehicles), can be of manyshapes or types. One shape of door in HVAC units can be barrel typedoors, i.e. doors that are shaped like a barrel and turn around acentral axis to distribute air.

U.S. Application Publication 2004/0016536A1, Auer et al, Jan. 29, 2004 asimple blend door (34) without any air mixture structure of any kind inthe unit, is described.

In the invention of U.S. Pat. No. 5,988,263, issued Nov. 23, 1999,Schwarz, an air flow mixer structure for a vehicle air conditioningsystem having a first conduit for a first air flow, a second conduit fora second air flow, an opening between said first and second conduits formerging said first and second air flows in a merging region and a commonair channel for said merged air flows wherein the mixer structure isdisposed in the first conduit for controlling the first air flow, themixer structure having an air inlet region and an air outlet regionopening into said merging region, the mixer structure comprising pluralair passages disposed between said inlet region and said outlet regionfor dividing an air flow at said inlet region into plural air flows atplural said openings into said merging region is described. In FIG. 2 ofU.S. Pat. No. 5,988,263 the air flow mixer structure is clearly locatedapart from the blend door feature, provided in a second duct in the airconditioning system, and not as an integrated assembly.

A further desired goal of such systems is to provide selected desiredair mixing at the output of the flow mixture structure. The prior art,therefore, shows that to design a compact HVAC unit architecture, thepositioning of the components is critical. These components aretypically heater core, evaporator, blend door (s), panel (vent) door andfloor door. In addition, as to the HVAC unit, itself prior todistribution through ducts and panel, defrost, or floor doors, prior artdesigns have had separate air mixing devices and blend door, positionedin series or in line one with another to achieve their desired air floweffects. This positioning leads to increased packaging space needs toachieve their desired end results.

A prior art HVAC system is shown in FIG. 1. The HVAC system's coremodule 12 and air distribution module 30. Ambient outside air orrecirculated interior air is directed to air inlet 14 and issubsequently directed through air-conditioning evaporator 16 by the HVACblower (not shown). After the air exits from evaporator 16 to passbetween point 19 and wall 20, part of the air is directed through coolinlet area 22- and part of the air directed to warm air passage 24.Inlet 22 and passage 24 are variable in area depending upon the positionof air mix door 18. Air mix door 18 is hinged at 17 to pivot therearound and the position of air mix door 18 is directly related to thedesired air temperature of air to be output to the interior of thevehicle. Thus, to obtain the maximum amount of cool air, air mix door 18is rotated to maximize the amount of cool air inlet 22. If heated air isdesired, air mix door 18 is rotated to create a warm air passage 24thereby diverting a portion of the air flow exiting from evaporator 16to flow through heater core 26 and duct the heated air through heatedair inlet 28 An intermediate position of air mix door 18 facilitates amixture of cool and hot air simultaneously entering air chamber 32 ofair distribution module 30 to provide air at a desired temperature.

Air distribution module 30 typically has three designated outlets fordelivering the conditioned air to different portions of the vehicle.These outlets are generally referred to as a defrost outlet 36 fordelivering air to the interior surface of the windshield, vent outlet 40for delivering air to the upper portion of the vehicle interior and aheater outlet 44 for delivering air to the foot wells of the vehicleinterior. Valves 34, 38 and 42 are selectively positionable in closed,opened or intermediate positions to place the desired HVAC in thedesired function. The HVAC system 10 is typically located in the centerof the vehicle as are outlets 36, 40 and 44.

In the past, many HVAC systems have been devised wherein multiplechambers exist to provide heated and/or cooled air to different areas ofthe passenger compartment of the vehicle. A large housing space was thusneeded in such systems. Typically, a control means has been used toregulate the positions of the outlet means, such as doors, to let airinto mixing chambers where the desired air temperature for the differentpassenger compartment areas (for example, the front and rear passengercompartments) is achieved.

Doors are often used to allow air entry into multiple chambers, eachchamber providing a certain temperature level of air for transport toits associated passenger compartment. This has meant that a front doorand a separate ‘rear’ door, with appropriate air channeling mechanism,such as divided walls and the like, was needed to direct the desiredtemperature air to both the rear and front areas of the passengercompartment. The air flow mixer concept meant that air could reach thehot and cold flow already partially mixed or turbulated. This mixingmeans that when cold air stream confronts warm air stream, the airintermingles more readily than in traditional systems. However, in theprior art systems, the mixing required a certain amount of space toconfront the ‘mixed’ and ‘non-mixed’ air.

As described above, customers demand designs with less and less spacerequired, so modern vehicles packaging requires more and moreintegration of the architecture. However, designs, including designswith baffles or, in particularly cross flow baffles such as thosedescribed in U.S. Application 2003/0201046, Oct. 20, 2003, Perry et aldescribe, for example, a cross flow distribution door (see FIG. 7)separate from any blend door. In current designs, the general design isto have the simple and separate blend door due to the heretoforeinability to provide designs with air mixing devices that provided thedesired temperature and air mixes necessary in limited spaces beforereaching, for example, air distribution areas and eventual distributionthrough ducts and panel, defrost or floor doors.

The present invention, therefore, solves the space problem whileproviding excellent volume and temperature of air conditioner in thesystem, by mounting an air mixer structure or ‘baffle’, and, inparticular, a cross flow air mixer structure, allowing direction of ordeflection of air flows prior to reaching the distribution area or,cross flow baffle inside a door as opposed to separate from the door asin the prior art, for automotive HVAC units. More specifically bylocating the baffle inside the door (baffle/barrel door assembly) itreduces packaging space requirements, allows for the attachment of thebaffle while allowing the door to function throughout its range ofmotion, and provides an easily manufacturable attachment means to locateor incorporate a baffle in a door, while providing for efficient mixingof air in the confined space of the HVAC unit.

Another problem with prior art barrel doors, however, is when they reachcritical lengths (for example, when they have a length from point ofattachment to point of attachment that that allows a significant amountof air to be directed into the distribution area at one time), they haveproblems due to increased flexibility. The prior art solution to thisproblem has been to place a shaft or other sort of similar bridgingdevice to stop the wedges, i.e. the ‘pizza’ like shape of the barreldoor, from flexing during assembly and to provide additional stiffness.The problem with such as shaft has often been that it resulted inunacceptable levels of turbulence off the shaft leading to undesirablenoises and air flow degradation. Such shaft, additionally, are often notsimple to mold, and thus, increase the complexity to manufacture of thedoor.

OBJECTS OF THE INVENTION

In view of the drawbacks and disadvantages identified in the prior art,it is an object of the present invention to provide a simpler and morereliable mechanism for both mixing and controlling air in HVAC unit. Thepresent invention, particularly in its preferred embodiments, solves theproblem of the need for both a separate door and separate air mixerstructure or ‘baffle’ within the limited packaging space of modern HVACunits. By providing for a blend door, or, more preferably, a blendbarrel door, incorporating or including an air mixer structure orbaffle, the blend barrel door/baffle arrangement thereby occupying,essentially, the same space in the HVAC unit as the blend barrel alone.The present invention decreases the number of separate elementsnecessary to provide appropriate mixing of air, as well as simplifying,reducing the space requirements of, and reducing the overall cost of thesystem.

It is a further object of the present invention to improve thecompression and torsion stiffness of a preferable barrel door withoutthe use of a shaft or cross member (whether it be molded in or not).

It is also a further object of the present invention to have an improvedassembly process for the blend doors and air mixing devices of HVACunits by aiding in the sealing function. By closability or sealing it ismeant prevention of flow past a normally open space. If there isinappropriate sealing, unwanted airflow passes, as might occur wherethere are areas of undesired torsion or twist.

SUMMARY OF THE INVENTION

The present invention meets the above needs by providing an airdistribution module for a vehicle heating, ventilation and airconditioning system wherein said module mixes hot and cold air streamsin a small HVAC unit space, as well as directs the air in the HVAC unitfor automotive use. The air of the airflow is mixed in the singlechamber prior to distribution to the front and rear passenger areas of avehicle interior. The air distribution module preferably furthercomprises an evaporator means and heater means, more preferably aevaporator or heat core or the like. Preferably, an air distributionmodule for a vehicle heating, ventilation and air conditioning system inaccordance with the present invention comprises a housing; a heatingmeans; a cooling or ‘evaporator’ means; a door; a baffle; a firstconduit for a first air flow; a second conduit for a second air flow; anopening between said first and second conduits for merging said firstand second airflows in a mixing region. Preferably the baffle is locatedwithin the door, forming a baffle/blend door assembly.

As stated above, preferably, the air mixer structure is located withinthe blend door, more preferably within a blend barrel door, when used inautomotive HVAC units.

In a preferred mode of operation, the blend door, and, preferably theblend barrel door, would be located downstream of the heater core andevaporator and would move between air passages for hot air from theheater core and cold air from the evaporator. The axis of the door wouldbe downstream of the passages that are blocked by the door. Located orincorporated within the blend door is an air mixer structure ‘baffle’.The baffle would fit into or occupy space in the interior of the door,and, preferably, fit into the door in the space between the triangularsides of the barrel. The baffle may be attached or functionally fittedinto the housing; preferably the baffle is attached to the housing bymeans of sliding into housing surfaces located downstream of thepassages that are blocked by the door. Also preferred is an airdistribution module for a vehicle heating, ventilation and airconditioning system in accordance with the present invention wherein thebarrel door is essentially in the shape of a ‘slice’ of a hollowcylinder closed on both ends. The shape has open space between thetriangular sides and fits into the open space that, in the past, wasessentially not used for packaging other components. This inventionpresents a solution to this problem by mounting an air mixer structure(baffle), preferably a cross flow baffle, in the essentially unusedspace inside a barrel door. The functions of mixing the hot and cold airpaths, performed by the baffle, and the directing of the mixed air,performed by the barrel door, are accomplished in much less packagingvolume than if the two components were not located together orintegrated.

In general, because the door must move through an arc to function andthe sides of the door sweep through the area that would be required tomount an object inside the door, the present invention, with its bafflelocated within the barrel door, presents the advantage of not requiringas much packaging volume as is typically allowed in common HVACarchitectures.

Overall, the present invention provides advantages over the prior artsuch as easier assembly; good sealing less torsion over-twist (i.e. poorsealing due to twist door twist or distorsion due to torque forms withinthe door in ability to mold geometric form); ease in manufacture;reduction of noise overall in the HVAC unit; use of a common ‘door’(combining the air mixing plus air distribution means) by a commonbaffle/barrel door assembly; baffle in-door technology leading tofurther competitive advantage due to compactness in the HVAC design; andallowance of removal of additional material, such as ‘shafts’ and thelike in typical barrel doors.

BRIEF DESCRIPTION OF THE DRAWINGS

The features and inventive aspects of the present invention will becomemore apparent upon reading the following detailed description, claims,and drawings, of which the following is a brief description:

FIG. 1 is an elevational cross sectional view of an exemplary prior artHVAC;

FIG. 2 is an elevational cross sectional view of another exemplary priorart HVAC;

FIG. 3 is an elevational cross sectional view of an exemplary HVAC inaccordance with an aspect of the present invention;

FIG. 4 is a cross sectional view of another exemplary HVAC in accordancewith an aspect of the present invention, and

FIG. 5 is a cross sectional view of an exemplary HVAC in accordance withan aspect of the present invention.

FIG. 6 a is a representation of a flat ‘pizza’ door from isometric andside views as found in the prior art.

FIG. 6 b is a representation of compound curvature ‘pizza’ door fromisometric and side views in accordance with an aspect of the presentinvention.

FIGS. 7 a and 7 b are a prior art barrel door without baffle, used inthe prior art, with high stress region shown.

FIG. 8 is a blend barrel door, having compound curvature, showing pizzaend piece and fixed or variable fillet and the curvature functions, inaccordance with an aspect of the present invention.

FIGS. 9 and 10 are different elevational views of blend/baffleassemblies, with cross flow baffle and blend barrel door componentsillustrated.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

Preferred embodiments of the air distribution module for a vehicleheating, ventilation and air conditioning system, therefore, comprise ahousing; a heating means such as a heater core or the like; anevaporator means such as an evaporator or the like; a door; a baffle; afirst conduit for a first air flow; a second conduit for a second airflow; an opening between said first and second conduits for merging saidfirst and second airflows in a mixing region. Preferably the door is ablend door. More preferably the door is functionally described as ablend door, and is in the shape of a barrel (‘blend barrel door’). Inthe preferred embodiments of the present invention, the door has withinits area formed by it inner surface (the surface where air passes bybefore being appropriately distributed to the distribution regions) anair mixture structure, (one type thereof herein defined as a baffle),yielding a baffle is located within the door. Even more preferably thedoor is a barrel door, and, even more preferably, a blend barrel door(blend door with a barrel shape) and the baffle located or incorporatedin the door is a cross flow baffle.

In preferred embodiments of the present invention, it has been foundthat by combining or placing or otherwise locating a specific type ofair mixing device (a baffle, or, more specifically, a cross flow baffle)within a blend door, and, preferably, a blend barrel door (blend door ofbarrel shape), this eliminates many of the problems of the prior art.Firstly, the present invention, by forming an assembly of both the door,and particularly, the blend barrel door, with the air mixing device(baffle, or, preferably, a cross flow baffle), (the ‘baffle/blend doorassembly’) the need for two elements (the air mixing device, anddownstream, the blend door) is eliminated. The blend barrel doorcontaining the cross flow baffle, as a baffle/blend door assembly, meansthat less space is required than would be if they were placed separatelyin line with one another. Secondly, and surprisingly, the air that comesout of the blend door/baffle assembly, especially when a cross flowbaffle is part of the assembly, yields air with the desiredcharacteristics prior to distribution, though counterintuitively onemight think that the fact that some of the air was being ‘mixed’ withinthe door would lead to difficulties in insuring that the air's finaltemperature and volume requirements to the distribution area would bemet, prior to the final distribution via mode doors and ducts to theinterior of the vehicle. A cross flow baffle specifically provide ageometry while allows entry of air into an area or zone from more thanone direction or stream and cross through or flow across each other in acontrolled manner, and exit the area or zone with predetermined and/orpredictable amount of mixing. Also preferred is wherein the baffle/blenddoor assembly is downstream of the heater means and the evaporatormeans.

In even more preferred embodiments of the present invention, thepresence of a baffle, and, particularly, a cross flow baffle, within theblend door, and, particularly, in the blend barrel door, have allowedfor blend barrel doors that no longer require a shaft or similar deviceto obtain the stiffness and sealing required. A shaft is no longerrequired, as in the prior art, to stop the ‘pizzas’ which are holdingthe ends of the door from flexing in during assembly, or to improvetorsion stiffness.

By providing for a blend barrel door with integrated cross flow baffle,the final result is an increase in overall quietness of the unit, easiermanufacturability, and increased overall quality. In the addition, theinternal space required is reduced, as the air mixing device and blenddoor are combined into one assembly or ‘unit’ thus leading to overallsavings. The space of importance in the HVAC, prior to the distributionarea of the HVAC unit, that was taken up by an air mixing device priorto a door, is reduced, and, by using a barrel door, the space within thebarrel door is occupied by the baffle, and, preferentially, the crossflow baffle, allowing the mixing (cross flow) baffle to be positioned inthis space to create a very compact overall design.

In preferred embodiments of the present invention, the cross flow baffle/blend barrel door assembly provides identical, if not better,characteristics, for air arriving at the air distribution area. Thecross flow baffle blend/barrel door assembly can be improved to provideincreased stiffness by using two generally perpendicular curved surfaces(compounds, surfaces) blended with a variable fillet at the juncture ofthe wedges or ‘pizzas’ where the surfaces meet, which support the doorends and the door itself. The compounding of the surfaces and this‘compound curvature’ gives tremendous geometrical advantage in thestiffness of the part. In these preferred embodiments of the presentinvention, this is achieved with no extra parts or any specific new orcomplex features. In preferred embodiments of the present invention, atleast one junction exists on each side of the barrel door at the area ofthe ‘wedges’ of the barrel door. Preferred is that the at least twoinner surfaces of the barrel door meet as a compound curvature and thatthe compound curvature is at a juncture with the wedge of the barreldoor. Even more preferred is when the compound surfaces or surfaces withat least two distinct planes of curvature are blended together with afillet. Even more preferred is when the fillet is a variable fillet.

The advantage of the stiffness improvement means easier assembly,quieter flow past the door. It allows the door to have a baffle insideit, where normally a large door width will dissuade the insertion of thebaffle in the door. Hence the architecture is more compact.

The area of meeting of two subtly curved or bended surfaces (alsoreferred to a compound curvature or compound surface) minimize stressconcentration in the area and hence minimize local strain whilestiffness stays high. The variable fillet allows the stresses to bespread throughout the whole region (area plus nearly regions of thedoor) rather than creation of the classical stress concentration at theedge of the pizzas and the door itself.

Curvature of the primary surface of the door structure needs to bepronounced (i.e. though subtle to the visual eye, apparent from astructural sense) to improve torsion stiffness. Curvature of the ‘pizza’(wedge shape) ends of the door or support pieces needs to be pronouncedto improve the flexural and or torsion stiffness of the door ends. Boththese structures need to be filleted or put together, preferably with avariable fillet, allowing stress to flow without peaks or abruptchanges.

In preferred embodiment of the present invention, by utilizing thegeometry available, even subtle changes in the curvature from previousor prior art planar type doors allows for a sturdier baffle/blend doorassembly in the HVAC module.

Referring to FIG. 1, there are a number of air outlets into the vehiclecabin and these outlets are connected to the air duct by a correspondingnumber of output ducts (two such ducts are shown in FIG. 1). A firstupper duct 41 is disposed on the side of the system which will tend toprovide cold air and the second lower duct 42 is disposed on the side ofthe system which will tend to provide hot air. Referring first to FIG.1, an evaporator unit 1 has an input side 2. Air is urged into the inputside 2 of the evaporator 1 by the movement of a vehicle in which the airconditioning system is mounted, or by a fan (not shown). The evaporator1 is disposed in an air duct 3 and the evaporator has an output side 4from which emerges cooled air. The output duct 3 extends to a throatportion 5 which co-operates with a blend door 10. The blend door asshown in FIG. 1 is in a central position so defining, with one wall of11 of the duct 3 a first conduit for cold air flow and, defining withthe opposite wall 12 of the duct 3 a second conduit for air which willbe heated. The second conduit leads to a heat exchanger core 20 which issupplied with hot water, for example from the engine of the vehicle, andwhich has an output side from which emerges a flow 21 of heated air. Theflow 21 of heated air and a cool air flow 22 from the first conduit cometogether in a mixing region 24 of the duct 3. Two distribution ducts, 41and 42 are shown in FIG. 1 and these, as has previously been discussedsupply air outlets in different parts of the vehicle cabin, e.g.passenger and driver's sides.

It would be understood by one skilled in the art that although somemixing of the hot and cold air flows will take place in the mixingregion 24, nonetheless the flow resistance caused by the heat exchangercore 20 will substantially reduce the velocity of the hot air and, as aresult, on the extreme left of the duct 3, as seen in the direction offlow, the cold air will predominate and, on the extreme right of theduct 3 as seen in the direction of flow, hot air will dominate. Thusdistribution duct 41 is more likely to contain cool air and distributionduct 42 is more likely to carry warm air.

In FIG. 2 is illustrated an HVAC system an air flow mixer structure 30is provided in the second conduit of the air conditioning system, on thedownstream side of the heater core. The air flow mixer structure has aninlet side 31, which is supplied in use with hot air from the heatercore and has an outlet side 32.

In FIGS. 3 and 4, there is illustrated a barrel door 101, essentially inis the shape of a ‘slice’ of a hollow cylinder closed on both ends 102,103. The inside surface of each of the ‘triangular’ sides 104, 105 hasslots 106, 107. The slots 106, 107 end in semi-circular shape and accepta pin 108, 109, and, in particular, a rounded or round pin, designedinto the air mixer structure 110 or baffle. The slots locate the bafflewith respect to the barrel door.

In FIGS. 4 and 5, there is illustrated a barrel door 101 and baffleassembly 110. The assembly is inserted into one side of the housing ofthe HVAC unit, preferably in a direction parallel to the axis of thebarrel door. The housing engages or ‘traps’ the baffle into the slots inthe barrel door by means of contacting surfaces 111, 112 between thebaffle and the housing. The contacting surfaces 111, 112 are essentiallyin a plane parallel to the axis of the barrel door, but normal to thedirection of the slot in the baffle. The envisioned structure is thatthe barrel door 101 would be located downstream of the heater core 113and evaporator 114 and would move between air passages for hot air fromthe heater core 113 and cold air from the evaporator 114. The axis 115of the door 101 would be downstream of the passages that are blocked bythe door. The baffle 110 would fit into the door, in the space betweenthe triangular sides of the barrel. The baffle 110 would attach to thehousing 116 by means of sliding into housing surfaces 111, 112 locateddownstream of the passages that are blocked by the door.

Preferably, the barrel door axis 115 is designed with a pin 117 thatfits into a hole 119 in the housing. This locates the door, preventingmovement in the plane of the slot on the door.

The opposite side of the housing is then placed over the barreldoor/baffle to mate with the first side of the housing. This housingalso has contacting surfaces to the baffle as described on the firsthousing. A second pin 118 on the axis of the barrel door fits into ahole 120 on the second housing 121, locating the barrel door along itsaxis.

In the preferred embodiments, the air mixer baffle is restricted orconstrained, more preferably restricted or constrained in all directionsand allows the blend barrel door to rotate about its axis.

The air mixer baffle is preferably designed so that it does notinterfere with the motion of the barrel door.

The simplified HVAC unit provides a baffle/blend door assemblycomprising an air mixer structure wherein the attachment means of baffleand barrel door is such that it provides for ease of assembly.

FIG. 6 a shows prior art flat pizza door in isometric (660 a, 660 c) andside (660 b, 660 d) views.

FIG. 6 b shows compound curved pizza door of the present invention inisometric (650 a, 650 c) and side (650 b, 650 d) views, showingcurvature.

Referring to FIG. 7 a, a flat barrel door 1014(a) with ends or bearings1012 is illustrated, the side view 1011 showing the pizza shape andtorsion shaft with end support 1013 illustrated.

Referring to FIG. 7 b, flat barrel door without shaft 1014 b is shown,with ends of door 1012, and area of high stress A illustrated.

FIG. 8 illustrates fixed or variable area or fillet 1000 and innersurface of the barrel door 1015 showing slight curvature 1016 in thedoor 1014 and compound curvature in the ‘pizza’ shaped end 1016. Sharedstress area B leads to additional strength and stability.

FIGS. 9 and 10 show air mixture structure 110 and barrel door 101 aspart of baffle/barrel door assembly 119. In FIGS. 9 and 10, there isillustrated a baffle/barrel door assembly 119 with barrel door 101,essentially in the shape of a ‘slice’ of a hollow cylinder 102 closed onboth ends. The inside surface of each of the ‘triangular’ sides 104, 105has slots 106, 107. The slots 106, 107 end in semi-circular shape andaccept a pin 108, 109, and, in particular, a rounded or round pin,designed into the air mixer structure 110 or baffle. The slots locatethe baffle with respect to the barrel door. Preferably, the barrel dooraxis is designed with a pin 117 that fits into a hole in the housing.This locates the door, preventing movement in the plane of the slot onthe door. Therefore, the baffle/blend door assembly is able to beassembled into the housing by sliding the assembly therein.

As described above, in preferred embodiments of the present invention,the baffle/blend door assembly preferably comprises a barrel door. Also,in preferred embodiments of the present invention, the baffle/blend doorassembly comprises a cross flow baffle. Most preferably, thebaffle/blend door assembly is a cross flow baffle/blend barrel door,i.e. it comprises a cross flow baffle located inside of a blend barreldoor.

In the embodiments of the present invention, the baffle, in addition tobeing found in the door, and, preferably, the barrel door, is attachedor functionally fitted into the housing. In more preferred embodiments,the baffle/blend door assembly comprises an attachment means of baffleand barrel door wherein the assembly can be attached to the housing bymeans of sliding.

In most preferred embodiments of the present invention, a baffle/blendbarrel door assembly for use in a vehicle heating, ventilation and/orair conditioning system is found that comprises a blend barrel door withat least two curved inner surfaces, and a cross flow baffle, wherein thecross flow baffle is integrated into the blend barrel door and whereinat least two curved inner surfaces form a compound curvature.

The attachment means of baffle and barrel door is such that it providesfor ease of assembly. The baffle/barrel door assembly provides forsmaller packaging volume with the same functionality as larger HVACunits.

The preferred embodiment of the present invention has been disclosed. Aperson of ordinary skill in the art would realize, however, that certainmodifications would come within the teachings of this invention.Therefore, the following claims should be studied to determine the truescope and content of the invention.

1. An air distribution module for a vehicle heating, ventilation and airconditioning system comprising: a housing; a heating means; anevaporator means; a door; a baffle; a first conduit for a first airflow; a second conduit for a second air flow; an opening between saidfirst and second conduits for merging said first and second airflows ina mixing region; wherein the baffle is located within the door.
 2. Anair distribution module according to claim 1 wherein the door is a blenddoor.
 3. An air distribution module according to claim 2 wherein theblend door is a barrel door.
 4. An air distribution module according toclaim 1 wherein the baffle is a cross-flow baffle.
 5. An airdistribution module according to claim 3 wherein the baffle is across-flow baffle.
 6. An air distribution module according to claim 3wherein at least two inner surfaces of the barrel door meet as acompound curvature.
 7. An air distribution module according to claim 6wherein the compound curvature occurs at a juncture of the wedge of thebarrel door.
 8. An air distribution module according to claim 7 whereinthe surfaces forming the compound curvature are blended together with afillet.
 9. An air distribution module according to claim 8 wherein thefillet is a variable fillet.
 10. An air distribution module for avehicle heating, ventilation and air conditioning system comprising: ahousing; a heating means; an evaporator means; a baffle/blend doorassembly; a first conduit for a first air flow; a second conduit for asecond air flow; an opening between said first and second conduits formerging said first and second airflows in a mixing region; wherein thebaffle/blend door assembly is downstream of the heater means and theevaporator means.
 11. An air distribution module according to claim 10wherein the baffle/blend door assembly comprises a barrel door.
 12. Anair distribution module according to claim 10 wherein the baffle/blenddoor assembly comprises a cross flow baffle.
 13. An air distributionmodule according to claim 11 wherein the baffle/blend door assemblycomprises a cross flow baffle.
 14. An air distribution module accordingto claim 13 wherein the baffle is attached or functionally fitted intothe housing.
 15. An air distribution module for a vehicle heating,ventilation and air conditioning system according to claim 14 whereinthe baffle/blend door assembly comprises an attachment means of baffleand barrel door wherein the assembly can be attached to the housing bymeans of sliding.
 16. An air distribution module according to claim 13wherein at least two inner surfaces of the barrel door meet as acompound curvature.
 17. An air distribution module according to claim 16wherein the compound curvature occurs at a juncture of the wedge of thebarrel door.
 18. An air distribution module according to claim 17wherein the surfaces forming the compound curvature are blended withfillet.
 19. An air distribution module according to claim 18 wherein thefillet is a variable fillet.
 20. A baffle/blend barrel door assembly foruse in a vehicle heating, ventilation and/or air conditioning systemcomprising a blend barrel door with at least two curved inner surfaces,and a cross flow baffle wherein the cross flow baffle is integrated intothe blend barrel door and wherein at least two curved inner surfacesform a compound curvature.